The field of art to which this invention pertains is the detoxification of high aqueous content hazardous waste streams. More particularly, the invention relates to the conversion and removal of hydrocarbonaceous compounds contained in high aqueous content hazardous waste streams which are hazardous or otherwise obnoxious. More specifically, the invention relates to a process for detoxifying a high aqueous content hazardous waste stream having a water content greater than about 70 weight percent and comprising halogenated hydrocarbonaceous compounds which comprises the steps of: (a) contacting the hazardous waste stream containing halogenated hydrocarbonaceous compounds in the presence of hydrogen and in the absence of a basic compound with a hydrogenation catalyst comprising a refractory support and at least one metal having hydrogenation activity and which metal is selected from the metals of Groups VI-B and VIII of the Periodic Table in a hydrotreating reaction zone operated at conditions selected to hydrogenate at least a portion of the halogenated hydrocarbonaceous compounds which conditions include a pressure from about 100 psig (2068 kPa gauge) to about 5000 psig (34475 kPa gauge), a maximum catalyst temperature from about 250.degree. F. (121.degree. C.) to about 850.degree. F. (454.degree. C.) and a hydrogen circulation rate from about 200 SCFB (35.6 std. m.sup.3 /m.sup.3) to about 10,000 SCFB (1778 std. m.sup.3 /m.sup.3); and (b) separating the effluent from the hydrotreating reaction zone in a gravitational separation zone to provide a hydrogenated hydrocarbonaceous stream and a detoxified aqueous stream.